1215651656 has 8 divisors (see below), whose sum is σ = 2279346870. Its totient is φ = 607825824.

The previous prime is 1215651653. The next prime is 1215651659. The reversal of 1215651656 is 6561565121.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1215651653) and next prime (1215651659).

It can be written as a sum of positive squares in only one way, i.e., 769174756 + 446476900 = 27734^2 + 21130^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (1215651653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 75978221 + ... + 75978236.

Almost surely, 2^1215651656 is an apocalyptic number.

It is an amenable number.

1215651656 is a deficient number, since it is larger than the sum of its proper divisors (1063695214).

1215651656 is a wasteful number, since it uses less digits than its factorization.

1215651656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151956463 (or 151956459 counting only the distinct ones).

The product of its digits is 54000, while the sum is 38.

The square root of 1215651656 is about 34866.1964659181. The cubic root of 1215651656 is about 1067.2587285154.

The spelling of 1215651656 in words is "one billion, two hundred fifteen million, six hundred fifty-one thousand, six hundred fifty-six".